JoseQ's Emu Views.
Great emulation page maintained by JoseQ, maker of the famous Rumor Mill, many downloads, great layout - some hosted sites.
http://www.emuviews.com/

KCemu - News.
An open source emulator of the KC85 homecomputer series for Linux and Windows.
http://kcemu.sourceforge.net/

The Computer History Simulation Project.
An open source collection of emulators for Windows of historical computers, including GRI-909, HP 2116/2100/21MX, IBM 1401/1620/1130/System 3, PDP-1/4/7-11/15/VAX. Also provides software kits, system photographs, and technical papers.
http://simh.trailing-edge.com/